Question 4General Subjects - 1st Asst/Chief

The correct answer is D) It is a control mode that produces a control action that is proportional to the error. In a closed-loop process control system, the proportional mode of control refers to a control action that is directly proportional to the magnitude of the error, or the difference between the desired setpoint and the actual process variable. The control action is adjusted linearly based on the error, with a higher error resulting in a greater control action to correct the process. This allows the system to respond quickly to changes and maintain the process at the desired setpoint. The other options describe different control modes (derivative and integral) that are not the defining characteristic of the proportional mode.